Washing machine appliances and methods for washing articles therein

ABSTRACT

Washing machine appliances and methods for washing articles in washing machine appliances are provided. A method includes flowing a hot water volume into a tub, wherein the hot water volume is the only water volume flowed at a hot temperature into the tub, and performing an agitation cycle after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub. The method further includes draining water from the tub after performing the agitation cycle, and flowing a cold water volume into the tub after draining the water from the tub. The method further includes draining water from the tub after flowing the cold water volume into the tub, and performing an extraction cycle after flowing the cold water volume into the tub and draining the water from the tub.

FIELD OF THE INVENTION

The present subject matter relates generally to washing machine appliances and methods for washing articles therein, and particularly to the sanitation of articles during washing thereof.

BACKGROUND OF THE INVENTION

Washing machine appliances generally include a cabinet which supports a tub for containing wash fluid, e.g., water and detergent, bleach and/or other wash additives. A basket is mounted within the tub and defines a wash chamber for receipt of articles for washing. During operation of such washing machine appliances, wash fluid is directed into the tub and onto articles within the wash chamber of the basket. The basket or an agitation element can rotate at various speeds to agitate articles within the wash chamber in the wash fluid, to wring wash fluid from articles within the wash chamber, etc.

Many washing machine appliances utilize sanitization cycles for generally sanitizing articles being washed therein. Historically, sanitization cycles utilized thermal sanitization, heating water in the tub to relatively high temperatures (such as above hot water temperatures, for example such as above 130 degrees Fahrenheit) for prolonged time periods to sanitize articles within the tub. However, such approaches are both energy and time intensive, resulting in overall wash cycles that can last over 2 hours and in some cases over 2.5 hours.

More recently, various additives in combination with specifically tailored sanitization cycles have been utilized to sanitize articles. U.S. Patent Application Publication No. 2015/0013075, filed on Jan. 15, 2015 and which is incorporated by reference herein in its entirety, discloses the use of additives with multiple hot water fills and multiple prolonged agitation periods for sanitization purposes. However, the requirements of multiple hot water fills and multiple prolonged agitation periods still require undesirably high energy and time investments.

An additional issue with presently known sanitization cycles is that the high temperature water utilized in such cycles can have an undesirable effect on some stains, such as blood. Rather than assisting in removing such stains from articles in the tub, the high temperature water can “lock-in” the stain.

Accordingly, improved washing machine appliances and methods for washing articles which provide improved sanitization cycles would be advantageous. In particular, improved sanitization at reduced time and energy levels would be desired. Further, improved stain removal in combination with sanitization would be desired.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one embodiment of the present disclosure, a method for washing articles in a washing machine appliance is provided. The washing machine appliance has a drum positioned within a tub. The drum defines a wash chamber for receipt of articles for washing. The method includes flowing a hot water volume into the tub to a predetermined fill level, wherein the hot water volume is the only water volume flowed at a hot temperature into the tub, and performing an agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub. The method further includes draining water from the tub after performing the agitation cycle, and flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub. The method further includes draining water from the tub after flowing the cold water volume into the tub, and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.

In accordance with another embodiment of the present disclosure, a method for washing articles in a washing machine appliance is provided. The washing machine appliance has a drum positioned within a tub. The drum defines a wash chamber for receipt of articles for washing. The method includes flowing a hot water volume into the tub to a predetermined fill level, wherein the hot water volume is at a temperature of between approximately 110 and approximately 130 degrees Fahrenheit and is the only water volume flowed at a hot temperature into the tub, and performing an agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub, the additive including an oxidizing agent. The method further includes flowing a cold water volume into the tub after performing the agitation cycle, wherein the cold water volume is at a temperature of between approximately 50 and approximately 80 degrees Fahrenheit, and performing a subsequent agitation cycle for a predetermined time period after flowing the cold water volume into the tub. The method further includes draining water from the tub after performing the agitation cycle and the subsequent agitation cycle, and flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub. The method further includes draining water from the tub after flowing the cold water volume into the tub, and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.

In accordance with another embodiment of the present disclosure, a method for washing articles in a washing machine appliance is provided. The washing machine appliance has a drum positioned within a tub. The drum defines a wash chamber for receipt of articles for washing. The method includes flowing a warm water volume into the tub to a predetermined fill level, and performing a first agitation cycle for a predetermined time period after flowing the warm water volume into the tub and after a detergent has been added to the tub. The method further includes flowing a hot water volume into the tub to a predetermined fill level, and performing a second agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after an additive has been added to the tub. The method further includes draining water from the tub after performing the second agitation cycle, and flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub. The method further includes draining water from the tub after flowing the cold water volume into the tub, and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.

In accordance with another embodiment of the present disclosure, a method for washing articles in a washing machine appliance is provided. The washing machine appliance has a drum positioned within a tub. The drum defines a wash chamber for receipt of articles for washing. The method includes flowing a warm water volume into the tub to a predetermined fill level, wherein the warm water volume is at a temperature of between approximately 70 and approximately 105 degrees Fahrenheit, and performing a first agitation cycle for a predetermined time period after flowing the warm water volume into the tub and after a detergent has been added to the tub. The method further includes flowing a hot water volume into the tub to a predetermined fill level, wherein the hot water volume is at a temperature of between approximately 110 and approximately 130 degrees Fahrenheit and is the only water volume flowed at a hot temperature into the tub, and performing a second agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub, the additive including an oxidizing agent. The method further includes flowing a cold water volume into the tub after performing the second agitation cycle, wherein the cold water volume is at a temperature of between approximately 50 and approximately 80 degrees Fahrenheit, and performing a third agitation cycle for a predetermined time period after flowing the cold water volume into the tub. The method further includes draining water from the tub after performing the third agitation cycle, and flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub. The method further includes draining water from the tub after flowing the cold water volume into the tub, and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.

In accordance with another embodiment of the present disclosure, a washing machine appliance is provided. The washing machine appliance includes a cabinet, a tub positioned within the cabinet, and a drum rotatably mounted within the tub, the drum defining a chamber for receipt of items for washing. The washing machine appliance further includes a motor in mechanical communication with the drum in order to selectively rotate the drum, and a controller in communication with the motor and the water inlet. The controller is configured for flowing a hot water volume into the tub to a predetermined fill level, wherein the hot water volume is the only water volume flowed at a hot temperature into the tub, and performing an agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub. The controller is further configured for draining water from the tub after performing the agitation cycle, and flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub. The controller is further configured for draining water from the tub after flowing the cold water volume into the tub, and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.

In accordance with another embodiment of the present disclosure, a washing machine appliance is provided. The washing machine appliance includes a cabinet, a tub positioned within the cabinet, and a drum rotatably mounted within the tub, the drum defining a chamber for receipt of items for washing. The washing machine appliance further includes a motor in mechanical communication with the drum in order to selectively rotate the drum, and a controller in communication with the motor and the water inlet. The controller is configured for flowing a warm water volume into the tub to a predetermined fill level, and performing a first agitation cycle for a predetermined time period after flowing the warm water volume into the tub and after a detergent has been added to the tub. The controller is further configured for flowing a hot water volume into the tub to a predetermined fill level, and performing a second agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after an additive has been added to the tub. The controller is further configured for draining water from the tub after performing the second agitation cycle, and flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub. The controller is further configured for draining water from the tub after flowing the cold water volume into the tub, and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of a washing machine appliance in accordance with one embodiment of the present disclosure;

FIG. 2 provides a schematic view of a washing machine appliance in accordance with one embodiment of the present disclosure; and

FIG. 3 provides a schematic view of certain components of a washing machine appliance in accordance with one embodiment of the present disclosure; and

FIG. 4 illustrates an exemplary method for washing articles in a washing machine appliance in accordance with one embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 illustrates an exemplary washing machine appliance 100. A drum 120 of washing machine appliance 100 rotates about a substantially horizontal axis. Thus, washing machine appliance 100 is generally referred to as a horizontal axis washing machine appliance 100. However, while described in the context of washing machine appliance 100, using the teachings disclosed herein, it will be understood that washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, such as vertical axis washing machine appliances.

Washing machine appliance 100 has a cabinet 102 with a tub 122 mounted therein. Tub 122 is configured for containing wash fluid during operation of washing machine appliance 100. Drum 120 is rotatably mounted within tub 122. Drum 120 extends between a top portion 146 (FIG. 2) and a bottom portion 148 (FIG. 2). Top and bottom portions 146 and 148 of drum 120 are, e.g., vertically, spaced apart from each other. A motor 142 (FIG. 3) is in mechanical communication with drum 120 in order to selectively rotate drum 120 (e.g., during an agitation, a spin, or a tumble cycle of washing machine appliance 100). Drum 120 defines a wash chamber 121 that is configured for receipt of articles for washing. Ribs 126 may extend from drum 120 into wash chamber 121. Ribs 126 assist with agitating articles disposed within wash chamber 121 during operation of washing machine appliance 100. For example, ribs 126 may lift articles disposed in drum 120 to top portion 146 of drum 120 during rotation of drum 120 and such articles may subsequently fall to bottom portion 148 of drum 120. Drum 120 also defines a plurality of holes 124. Holes 124 are configured to permit a flow of wash fluid and/or air between wash chamber 121 of drum 120 and tub 122. A detergent drawer 106 is slidably mounted within cabinet 102. Detergent drawer 106 receives detergent and directs the detergent to wash chamber 121 or tub 122 during operation of appliance 100. Detergent drawer 106 may further receive various additives as discussed herein and direct the additives to wash chamber 121 or tub 122 during operation of appliance 100.

Cabinet 102 of washing machine appliance defines an opening 105 that permits user access to wash chamber 121 of drum 120. A door 130 is mounted to cabinet 102 at opening 105 with a hinge 140. A window 136 in door 130 permits viewing of wash chamber 121 during operation of appliance 100. Door 130 also includes a handle 132 that, e.g., a user may pull when opening and closing door 130. Latch 134 is configured for selectively securing door 130 in a closed position.

A control panel 110 with a plurality of input selectors 112 is also mounted to cabinet 102. Control panel 110 and input selectors 112 collectively form a user interface for operator selection of machine cycles and features. A display 114 of control panel 130 indicates selected features, a countdown timer, and/or other items of interest to appliance users.

FIG. 2 provides a schematic view of one embodiment of washing machine appliance 100. As may be seen in FIG. 2, washing machine appliance 100 includes a cold water inlet 150 and a hot water inlet 152. Cold water inlet 150 is in fluid communication with a water source, such as a municipal water main or a well. Thus, cold water inlet 150 is configured for receipt of relatively cold water from the water source. A cold water conduit 154 extends between and fluidly connects cold water inlet 150 and detergent drawer 106. Thus, relatively cold water from cold water inlet 150 can flow through cold water conduit 154 to detergent drawer 106. Conversely, hot water inlet 152 is in fluid communication with a hot water source, such as a hot water heater. Thus, hot water inlet 152 is configured for receipt of relatively hot water from the hot water source. A hot water conduit 156 extends between and fluidly connects hot water inlet 152 and detergent drawer 106. Thus, relatively hot water from hot water inlet 152 can flow through hot water conduit 156 to detergent drawer 106. As will be understood by those skilled in the art and as used herein, the term “water” includes purified water and solutions or mixtures containing water and, e.g., elements (such as calcium, chlorine, and fluorine), salts, bacteria, nitrates, organics, and other chemical compounds or substances.

An inlet conduit 158 extends between and fluidly connects detergent drawer 106 and drum 120 or tub 122. Thus, fluid within detergent drawer 106 can flow through inlet conduit 158 into wash chamber 121 of drum 120 or tub 122. As an example, a user can add detergent and an additive, such as bleach, fabric softener, other additives as discussed herein, etc., to detergent drawer 106. Water from cold water inlet 150 and/or hot water inlet 152 can flow into detergent drawer 106 and mix with fluid additive to form a wash fluid. Such wash fluid can flow through inlet conduit 158 into wash chamber 121 of drum 120 or tub 122 in order to assist with cleaning articles disposed within wash chamber 121.

Washing machine appliance 100 also includes a sump 160, e.g., positioned at bottom portion 148 of drum 120 or a bottom portion (not shown) of tub 122 positioned at or proximate bottom portion 148 of drum 120. Liquids within wash chamber 121 can collect within sump 160 during operation of washing machine appliance 100, e.g., due to gravity. A drain conduit 162 is configured for directing liquids out of sump 160. In particular, a drain pump 164 is in configured for urging liquids out of sump 160 through drain conduit 162. Liquids within drain conduit 162 are directed out of washing machine appliance 100, e.g., to a sewer or septic system. In particular, drain pump 164 can urge liquids within sump 160 out of washing machine appliance 100 through drain conduit 162. As an example, drain pump 164 can be activated during a drain cycle of washing machine appliance 100 in order to remove dirty or used wash fluid from sump 160.

An exhaust conduit 166, e.g., positioned at top portion 146 of drum 120 or a top portion (not shown) of tub 122 positioned at or proximate top portion 146 of drum 120, is configured for directed gases, e.g., air, out of wash chamber 121 of drum 120 and/or tub 122. In particular, an air handler or fan 168 is in configured for urging gases out of wash chamber 121 of drum 120 and/or tub 122 through exhaust conduit 166. Gases within exhaust conduit 166 are directed out of washing machine appliance 100, e.g., to an exterior atmosphere. In particular, fan 168 can urge gases within wash chamber 121 of drum 120 and/or tub 122 out of washing machine appliance 100 through exhaust conduit 166. As an example, fan 168 can be activated after a wash cycle of washing machine appliance 100 in order to hinder mildew or mold growth within wash chamber 121 after the wash cycle.

FIG. 3 provides a schematic view of certain components of washing machine appliance 100. As may be seen in FIG. 3, washing machine appliance 100 includes a processing device or controller 144. Operation of washing machine appliance 100 is controlled by controller 144.

Controller 144 includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of washing machine appliance 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 144 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

Controller 144 is operatively coupled to various components of washing machine appliance 100. For example, washing machine appliance 100 includes control panel 110 for user manipulation to select washing machine cycles and features. Controller 144 is in communication with control panel 110. Thus, in response to user manipulation of control panel 110, controller 144 operates the various components of washing machine appliance 100 to execute selected machine cycles and features.

As an example, a user can load articles for washing into wash chamber 121, and the user can initiate washing operation through manipulation of input selectors 112 of control panel 110. Controller 144 then actuates cold water inlet 150 and/or hot water inlet 152 in order to fill drum 120 and/or tub 122 with water and/or detergent and additives to form a wash fluid in the manner discussed above. Once drum 120 and/or tub 122 is properly filled with wash fluid, controller 144 activates motor 142 in order to, for example, agitate the articles within wash chamber 121 with ribs 126 and assist with cleansing such articles.

After one or more agitation cycles of a wash cycle are completed, controller 144 activates drain pump 164 to remove wash fluid from drum 120 and/or tub 122. Articles can then be rinsed by adding relatively clean fluid to drum 120 and/or tub 122 and, depending on the particulars of the cleaning cycle selected by a user, ribs 126 may again provide agitation within wash chamber 121. One or more spin cycles may also be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed. During a spin cycle, drum 120 is rotated at relatively high speeds.

As mentioned, water can be flowed into drum 120 and/or tub 122 from cold water inlet 150 and/or hot water inlet 152. A volume of water, i.e., an amount of water that is provided into drum 120 and/or tub 122 during a single fill, can be a hot water volume and thus be at a hot temperature when flowed into the drum 120 and/or tub 122, or can be a warm water volume and thus be at a warm temperature when flowed into the drum 120 and/or tub 122, or can be a cold water volume and thus be at a cold temperature when flowed into the drum 120 and/or tub 122. A hot temperature, and thus the temperature of a hot water volume, may for example be between approximately 110 and approximately 130 degrees Fahrenheit, such as between approximately 115 and approximately 125 degrees Fahrenheit. A warm temperature, and thus the temperature of a warm water volume, may for example be between approximately 70 and approximately 105 degrees Fahrenheit, such as between approximately 75 and approximately 95 degrees Fahrenheit. A cold temperature, and thus the temperature of a cold water volume, may for example be between approximately 50 and approximately 80 degrees Fahrenheit, such as between approximately 55 and approximately 70 degrees Fahrenheit. A cold water volume may be obtained through operation of the cold water inlet 150 to flow water therethrough while not operating the hot water inlet 152. A hot water volume may be obtained through operation of the hot water inlet 152 to flow water therethrough while not operating the cold water inlet 150. A warm water volume may be obtained through operation of the cold water inlet 150 and the hot water inlet 152 to flow water therethrough.

FIG. 4 illustrates an exemplary method 200 for operating a washing machine appliance according to exemplary embodiments of the present subject matter. Such methods can advantageously provide improved washing machine appliance when sanitization of articles is required, by for example, advantageously requiring only a single hot water fill and/or utilizing relatively shorter time periods for particular agitation cycles. Further, such methods can advantageously provide improved stain removal by utilizing initial warm water fills when sanitization of articles is required, thus treating rather than “locking-in” certain stains such as blood stains. In exemplary embodiments, controller 144 can generally be programmed to implement such methods, and thus may be configured to perform the various steps thereof.

A method in accordance with the present disclosure may include, for example, the step 210 of flowing a warm water volume into the tub 122 to a predetermined fill level. The predetermined fill level is a total liquid level within the tub 122. The predetermined fill level may for example be dependent upon the article volume size, and thus for example may be based on the weight of the articles in the tub 122. For example, the predetermined fill level may be between approximately 0.4 and approximately 1.0 gallons per pound of articles within the tub 122. In some embodiments, the predetermined fill level may be between approximately 3 and approximately 7 gallons.

Method 200 may further include the step 212 of performing a first agitation cycle for a predetermined time period. Such step 212 may occur, for example, after step 210. Further, such step 212 may occur after a detergent has been added to the tub 122, such as via detergent drawer 106, by hand, or via another suitable delivery apparatus or method.

The first agitation cycle generally agitates the articles and wash fluid, including the warm water volume and detergent, within the tub 122. In exemplary embodiments, such step 212 may include rotating the drum 120 in the first agitation cycle. Alternatively, such step 212 may include rotating an agitation element relative to drum 120. Such rotation of the drum 120 or agitation element may include various steps of rotating and/or holding stationary to allow articles within the wash chamber 121 to soak within the wash fluid. For example, the first agitation cycle may include rotating for a rotation period of between approximately 5 seconds and approximately 20 seconds, such as between approximately 10 seconds and approximately 15 seconds, and may further include holding stationary for a soak period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 2 seconds and approximately 6 seconds. The rotations of drum 120 or agitation element may be performed at any suitable speeds, such as for example between approximately 30 revolutions per minute (“RPM”) and approximately 60 RPM, such as between approximately 40 RPM and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc. Further, additional or alternative patterns of rotation (at any suitable speeds) and/or holding may be utilized in a first agitation cycle as desired or required.

As discussed, the first agitation cycle may be performed for a predetermined time period. In exemplary embodiments, the predetermined time period may be between approximately 15 minutes and approximately 30 minutes, such as between approximately 15 and approximately 25 minutes.

As discussed, the use of warm water in accordance with steps 210 and 212 may advantageously facilitate improved stain removal, particularly in the case of stains such as blood which can become “locked-in” to associated articles rather than removed when hot water is utilized for stain removal.

Method 200 may further include the step 220 of flowing a hot water volume into the tub 122 to a predetermined fill level. The predetermined fill level may for example be dependent upon the article load size, and thus for example may be based on the weight of the articles in the tub 122. For example, the predetermined fill level may be between approximately 0.4 and approximately 1.0 gallons per pound of articles within the tub 122. In some embodiments, the predetermined fill level may be between approximately 3 and approximately 7 gallons.

Further, when steps 210 and 212 are included in the method 200, step 220 may occur after step 212. Hot water volume may be flowed into the tub 122 to raise the temperature of the existing water from step 210 to a desired activation temperature for an additive as discussed herein. Such activation temperature may, for example, be between approximately 90 degrees Fahrenheit and approximately 110 degrees Fahrenheit, such as between approximately 95 degrees Fahrenheit and approximately 105 degrees Fahrenheit. A suitable temperature sensor (not shown) within tub 122 and in communication with controller 144 may provide such temperature outputs to controller 144. The temperature may be raised to the activation temperature while not exceeding a predetermined fill level.

Method 200 may further include the step 222 of performing a second agitation cycle for a predetermined time period. Such step 222 may occur, for example, after step 220. Further, such step 222 may occur after an additive has been added to the tub 122, such as via detergent drawer 106, by hand, or via another suitable delivery apparatus or method. Additionally, in embodiments wherein steps 210 and 212 are not utilized, such step 222 may occur after a detergent has been added to the tub 122, such as via detergent drawer 106, by hand, or via another suitable delivery apparatus or method.

The second agitation cycle generally agitates the articles and wash fluid, including the hot water volume, detergent and additive, within the tub 122. In exemplary embodiments, such step 222 may include rotating the drum 120 in the second agitation cycle. Alternatively, such step 222 may include rotating an agitation element relative to drum 120. Such rotation of the drum 120 or agitation element may include various steps of rotating and/or holding stationary to allow articles within the wash chamber 121 to soak within the wash fluid. For example, the second agitation cycle may include rotating for a rotation period of between approximately 5 seconds and approximately 20 seconds, such as between approximately 10 seconds and approximately 15 seconds, and may further include holding stationary for a soak period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 2 seconds and approximately 6 seconds. The rotations of drum 120 or agitation element may be performed at any suitable speeds, such as for example between approximately 30 revolutions per minute (“RPM”) and approximately 60 RPM, such as between approximately 40 RPM and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc. Further, additional or alternative patterns of rotation (at any suitable speeds) and/or holding may be utilized in a second agitation cycle as desired or required.

As discussed, the second agitation cycle may be performed for a predetermined time period. In exemplary embodiments, the predetermined time period may be between approximately 15 minutes and approximately 30 minutes, such as between approximately 15 and approximately 25 minutes.

As discussed, an additive may be added to the tub 122, such as before step 222. The additive may include surfactants, emulsifiers, enzyme activated stain removers, sudsing agents, builders, anti-redeposition polymers and perfumes, etc., and may be an aqueous or non-aqueous solution or mixture. The additive in exemplary embodiments includes an oxidizing agent. Oxidizing agents are active oxygen releasing compound, e.g., peroxides (peroxygen compounds) such as perborate, percarbonates, perphosphates, persilicates, persulfates, their sodium, ammonium, potassium and lithium analogs, calcium peroxide, zinc peroxide, sodium peroxide, carbamide peroxide, hydrogen peroxide, and the like. These agents also include peroxy acids and organic peroxides and various mixtures thereof.

A peroxy acid is an acid in which an acidic —OH group has been replaced by an —OOH group. They are formed chiefly by elements in groups 14, 15 and 16 of the periodic table, but boron and certain transition elements are also known to form peroxy acids. Sulfur and phosphorus form the largest range of peroxy acids, including some condensed forms such as peroxydiphosphoric acid, H₄P₂O₈ and peroxydisulfuric acid, H₂S₂O₈. This term also includes compounds such as peroxy-carboxylic acids and meta-chloroperoxybenzoic acid (mCPBA).

Organic peroxides are organic compounds containing the peroxide functional group (ROOR′). If the R′ is hydrogen, the compound is called an organic hydroperoxide. Peresters have general structure RC(O)OOR. The O—O bond easily breaks and forms free radicals of the form RO.. This makes organic peroxides useful for cleaning purposes.

Oxidizing agents may be combined within a mixture that has a selection of other material, such as one or more of the following: builders, surfactants, enzymes, bleach activators, bleach catalysts, bleach boosters, alkalinity sources, antibacterial agents, colorants, perfumes, pro-perfumes, finishing aids, lime soap dispersants, composition malodor control agents, odor neutralizers, polymeric dye transfer inhibiting agents, crystal growth inhibitors, photobleaches, heavy metal ion sequestrants, anti-tarnishing agents, anti-microbial agents, anti-oxidants, linkers, anti-redeposition agents, electrolytes, pH modifiers, thickeners, abrasives, divalent or trivalent ions, metal ion salts, enzyme stabilizers, corrosion inhibitors, diamines or polyamines and/or their alkoxylates, suds stabilizing polymers, solvents, process aids, fabric softening agents, optical brighteners, hydrotropes, suds or foam suppressors, suds or foam boosters, fabric softeners, antistatic agents, dye fixatives, dye abrasion inhibitors, anti-crocking agents, wrinkle reduction agents, wrinkle resistance agents, soil release polymers, soil repellency agents, sunscreen agents, anti-fade agents, water soluble polymers, water swellable polymers and mixtures thereof.

In exemplary embodiments, the oxidizing agent is or includes sodium percarbonate, such as between approximately 30 and approximately 50 percent sodium percarbonate. In exemplary embodiments when the additive is added to the tub 122, the oxidizing agent may be greater than or equal to 0.3 grams per liter of wash fluid within the tub 122. Further, in exemplary embodiments, the additive may further include, for example, a bleach activator component such as sodium nonanoyloxybenzenesulfonate (NOBS), tetraacetylethylenediamine (TAED), or decanoyloxybenzoic acid (DOBA). In exemplary embodiments, the additive may include between approximately 1% and approximately 7% bleach activator. Suitable commercially available additives include, for example, OxiClean® products and Clorox 2® products.

Notably, in exemplary embodiments, the hot water volume utilized in step 220 may be the only water volume that is flowed at a hot temperature into the tub 122, and thus the only hot water volume utilized during an overall wash cycle that utilizes method 200. Accordingly, in exemplary embodiments, any water volume other than the hot water volume utilized in step 220 is either a cold water volume or a warm water volume. The present inventors have discovered that the use of a single hot water volume in accordance with the present disclosure and in combination with detergent and an additive as discussed herein can advantageously reduce common bacterial levels by, for example, 99.9%. Accordingly, use of a single hot water volume is advantageously sufficient to provide desired sanitization of articles in the volume. Such approach to sanitization advantageously reduces the energy and time levels associated with such sanitization while advantageously retaining the desired sanitization properties.

Method 200 may further include, for example, the step 224 of draining water (as well as detergent and additive) from the tub 122. Drain conduit 162 and drain pump 164 may, for example, be utilized to drain such water, etc. as discussed above. Such step 224 may, for example, occur after step 222. In some embodiments, step 224 may occur directly after step 222. In other embodiments, additional steps as discussed herein may occur before step 224.

For example, method 200 may further include, for example, the step 230 of flowing a cold water volume into the tub 122. Such step 230 may occur, for example, after step 222. Additionally, such step 230 may occur before step 224. In exemplary embodiments, cold water volume may have a predetermined size, such as for example, between approximately 0.2 and approximately 0.8 gallons. The size of the cold water volume may be small relative to the predetermined fill level of steps 210 and/or 220, and may for example, be utilized simply as a flush of the detergent drawer 106 and/or other suitable dispensing apparatus for bleach, other additives, etc.

Method 200 may further include the step 232 of performing a third agitation cycle for a predetermined time period. Such step 232 may occur, for example, after step 230 (and before step 224). The third agitation cycle generally agitates the articles and wash fluid, including the water volume from steps 210 and/or 220, detergent and additive, and the cold water volume from step 230, within the tub 122. In exemplary embodiments, such step 232 may include rotating the drum 120 in the third agitation cycle. Alternatively, such step 232 may include rotating an agitation element relative to drum 120. Such rotation of the drum 120 or agitation element may include various steps of rotating and/or holding stationary to allow articles within the wash chamber 121 to soak within the wash fluid. For example, the third agitation cycle may include rotating for a rotation period of between approximately 5 seconds and approximately 20 seconds, such as between approximately 10 seconds and approximately 15 seconds, and may further include holding stationary for a soak period of between approximately 2 seconds and approximately 10 seconds, such as between approximately 2 seconds and approximately 6 seconds. The rotations of drum 120 or agitation element may be performed at any suitable speeds, such as for example between approximately 30 revolutions per minute (“RPM”) and approximately 60 RPM, such as between approximately 40 RPM and approximately 50 RPM. Such rotation and holding may be repeated as required, and repeated rotations may occur in opposite directions, such as clockwise, then counterclockwise, then clockwise, etc. Further, additional or alternative patterns of rotation (at any suitable speeds) and/or holding may be utilized in a third agitation cycle as desired or required.

As discussed, the third agitation cycle may be performed for a predetermined time period. In exemplary embodiments, the predetermined time period may be between approximately 5 minutes and approximately 20 minutes, such as between approximately 5 and approximately 15 minutes.

As discussed, draining step 224 may occur after step 222, as well as for example after step 232. Method 200 may further include, for example, the step 226 of performing a first extraction cycle for a predetermined time period. Such step 226 may occur, for example, after step 224. In exemplary embodiments, such step 226 may include rotating the drum 120 in the first extraction cycle. The first extraction cycle may extract water (as well as detergent and additive) from the articles within the wash chamber 121. Rotation of the drum 120 in the first extraction cycle may occur for example at a generally higher speed than any of the agitation cycle discussed herein, such as for example between approximately 300 RPM and approximately 1200 RPM. The predetermined time period for the first extraction cycle may, for example, be between approximately 5 minutes and approximately 15 minutes.

Method 200 may further include, for example, the step 240 of flowing a cold water volume into the tub 122 to a predetermined fill level. Such step 240 may occur, for example, after steps 224 and 226. The predetermined fill level is a total liquid level within the tub 122. The predetermined fill level may for example be dependent upon the article load size, and thus for example may be based on the weight of the articles in the tub 122. For example, the predetermined fill level may be between approximately 0.4 and approximately 1.0 gallons per pound of articles within the tub 122. In some embodiments, the predetermined fill level may be between approximately 3 and approximately 7 gallons.

In some embodiments, methods 200 may further include, for example, the step of performing a fourth agitation cycle for a predetermined time period. Such step may, for example, occur after step 240. The fourth agitation cycle may for example be performed in accordance with the variables of the first, second or third agitation cycles as discussed above. In exemplary embodiments, the predetermined time period may for example be between approximately 1 minute and approximately 5 minutes.

Method 200 may further include, for example, the step 242 of draining water (as well as detergent and additive) from the tub 122. Drain conduit 162 and drain pump 164 may, for example, be utilized to drain such water, etc. as discussed above. Such step 242 may, for example, occur after step 240 as well as after the optional agitation step subsequent to step 240.

Method 200 may further include, for example, the step 244 of performing a subsequent second extraction cycle for a predetermined time period. Such step 244 may occur, for example, after step 240, the optional agitation step subsequent to step 240, and step 242. In exemplary embodiments, such step 244 may include rotating the drum 120 in the second extraction cycle. The second extraction cycle may extract water (as well as detergent and additive) from the articles within the wash chamber 121. Rotation of the drum 120 in the second extraction cycle may occur for example at a generally higher speed than any of the agitation cycle discussed herein, such as for example between approximately 300 RPM and approximately 1200 RPM. The predetermined time period for the second extraction cycle may, for example, be between approximately 5 minutes and approximately 15 minutes.

In some embodiments, upon ceasing of step 244, the overall wash cycle may end. Alternatively, a second series of steps may be utilized to further rinse the articles and thus remove remaining detergent and/or additive and to repeat the subsequent extraction. Accordingly, methods 200 may further include, for example, the step 250 of flowing a cold water volume into the tub 122 to a predetermined fill level. Such step 250 may occur, for example, after step 244. The predetermined fill level is a total liquid level within the tub 122. The predetermined fill level may for example be dependent upon the article load size, and thus for example may be based on the weight of the articles in the tub 122. For example, the predetermined fill level may be between approximately 0.4 and approximately 1.0 gallons per pound of articles within the tub 122. In some embodiments, the predetermined fill level may be between approximately 3 and approximately 7 gallons.

In some embodiments, methods 200 may further include, for example, the step of performing a fifth agitation cycle for a predetermined time period. Such step may, for example, occur after step 250. The fifth agitation cycle may for example be performed in accordance with the variables of the first, second, third or fourth agitation cycles as discussed above. In exemplary embodiments, the predetermined time period may for example be between approximately 1 minute and approximately 5 minutes.

Method 200 may further include, for example, the step 252 of draining water (as well as detergent and additive) from the tub 122. Drain conduit 162 and drain pump 164 may, for example, be utilized to drain such water, etc. as discussed above. Such step 252 may, for example, occur after step 250 as well as after the optional agitation step subsequent to step 250.

Method 200 may further include, for example, the step 254 of performing a subsequent third extraction cycle for a predetermined time period. Such step 254 may occur, for example, after step 250, the optional agitation step subsequent to step 250, and step 252. In exemplary embodiments, such step 254 may include rotating the drum 120 in the third extraction cycle. The third extraction cycle may extract water (as well as detergent and additive) from the articles within the wash chamber 121. Rotation of the drum 120 in the third extraction cycle may occur for example at a generally higher speed than any of the agitation cycle discussed herein, such as for example between approximately 300 RPM and approximately 1200 RPM. The predetermined time period for the third extraction cycle may, for example, be between approximately 5 minutes and approximately 15 minutes.

In some embodiments, upon ceasing of step 254, the overall wash cycle may end. Alternatively, a third or more series of steps may be utilized to further rinse the articles and thus remove remaining detergent and/or additive and to repeat the subsequent extraction. In exemplary embodiments, upon ceasing of such steps, the overall wash cycle may end.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A method for washing articles in a washing machine appliance, the washing machine appliance having a drum positioned within a tub, the drum defining a wash chamber for receipt of articles for washing, the method comprising: flowing a hot water volume into the tub to a predetermined fill level, wherein the hot water volume is the only water volume flowed at a hot temperature into the tub; performing an agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub; draining water from the tub after performing the agitation cycle; flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub; draining water from the tub after flowing the cold water volume into the tub; and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.
 2. The method of claim 1, wherein performing the agitation cycle comprises rotating the drum in the agitation cycle and wherein performing the extraction cycle comprises rotating the drum in the extraction cycle.
 3. The method of claim 1, wherein the hot water volume is at a temperature of between approximately 110 and approximately 130 degrees Fahrenheit.
 4. The method of claim 1, wherein the predetermined time period for performing the agitation cycle is between approximately 15 and approximately 30 minutes.
 5. The method of claim 1, wherein the cold water volume is at a temperature of between approximately 50 and approximately 80 degrees Fahrenheit.
 6. The method of claim 1, further comprising: flowing a cold water volume into the tub after performing the agitation cycle and before draining the water; and performing a subsequent agitation cycle for a predetermined time period after flowing the cold water volume into the tub and before draining the water.
 7. The method of claim 6, wherein the predetermined time period for performing the subsequent agitation cycle is between approximately 5 and approximately 15 minutes.
 8. The method of claim 1, further comprising: flowing a subsequent cold water volume into the tub to a predetermined fill level after performing the extraction cycle; draining water from the tub after flowing the subsequent cold water volume into the tub; and performing a subsequent extraction cycle for a predetermined time period after flowing the subsequent cold water volume into the tub and draining the water from the tub.
 9. The method of claim 1, wherein the additive comprises an oxidizing agent.
 10. The method of claim 9, wherein the oxidizing agent is greater than or equal to 0.3 grams per liter of wash fluid within the tub.
 11. A method for washing articles in a washing machine appliance, the washing machine appliance having a drum positioned within a tub, the drum defining a wash chamber for receipt of articles for washing, the method comprising: flowing a hot water volume into the tub to a predetermined fill level, wherein the hot water volume is at a temperature of between approximately 110 and approximately 130 degrees Fahrenheit and is the only water volume flowed at a hot temperature into the tub; performing an agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub, the additive comprising an oxidizing agent; flowing a cold water volume into the tub after performing the agitation cycle, wherein the cold water volume is at a temperature of between approximately 50 and approximately 80 degrees Fahrenheit; performing a subsequent agitation cycle for a predetermined time period after flowing the cold water volume into the tub; draining water from the tub after performing the agitation cycle and the subsequent agitation cycle; flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub; draining water from the tub after flowing the cold water volume into the tub; and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.
 12. The method of claim 11, wherein performing the agitation cycle comprises rotating the drum in the agitation cycle and wherein performing the extraction cycle comprises rotating the drum in the extraction cycle.
 13. The method of claim 11, wherein the predetermined time period for performing the agitation cycle is between approximately 15 and approximately 30 minutes.
 14. The method of claim 11, wherein the predetermined time period for performing the subsequent agitation cycle is between approximately 5 and approximately 15 minutes.
 15. The method of claim 11, further comprising: flowing a subsequent cold water volume into the tub to a predetermined fill level after performing the extraction cycle; draining water from the tub after flowing the subsequent cold water volume into the tub; and performing a subsequent extraction cycle for a predetermined time period after flowing the subsequent cold water volume into the tub and draining the water from the tub.
 16. The method of claim 11, wherein the oxidizing agent is greater than or equal to 0.3 grams per liter of wash fluid within the tub.
 17. A washing machine appliance, comprising: a cabinet; a tub positioned within the cabinet; a drum rotatably mounted within the tub, the drum defining a chamber for receipt of items for washing; a motor in mechanical communication with the drum in order to selectively rotate the drum; and a controller in communication with the motor and the water inlet, the controller configured for: flowing a hot water volume into the tub to a predetermined fill level, wherein the hot water volume is the only water volume flowed at a hot temperature into the tub; performing an agitation cycle for a predetermined time period after flowing the hot water volume into the tub and after a detergent and an additive have been added to the tub; draining water from the tub after performing the agitation cycle; flowing a cold water volume into the tub to a predetermined fill level after draining the water from the tub; draining water from the tub after flowing the cold water volume into the tub; and performing an extraction cycle for a predetermined time period after flowing the cold water volume into the tub and draining the water from the tub.
 18. The washing machine appliance of claim 17, wherein the controller is further configured for: flowing a cold water volume into the tub after performing the agitation cycle and before draining the water; and performing a subsequent agitation cycle for a predetermined time period after flowing the cold water volume into the tub and before draining the water.
 19. The washing machine appliance of claim 18, wherein the predetermined time period for performing the agitation cycle is between approximately 15 and approximately 30 minutes and wherein the predetermined time period for performing the subsequent agitation cycle is between approximately 5 and approximately 15 minutes.
 20. The washing machine appliance of claim 17, wherein the hot water volume is at a temperature of between approximately 110 and approximately 130 degrees Fahrenheit and wherein the cold water volume is at a temperature of between approximately 50 and approximately 80 degrees Fahrenheit. 